Self-Suturing Anchors

ABSTRACT

Apparatus and methods are provided, including a plurality of anchoring elements, each of the anchoring elements being an elongate element that is curved to define an opening. A housing holds each of the anchoring elements. A mandrel is reversibly disposable through the openings defined by the anchoring elements. The anchoring elements are configured such that, in response to removal of the mandrel from the openings, ends of the anchoring elements automatically move outwardly, and diameters of the openings decrease, due to elastic loading of the anchoring elements. Other embodiments are also described.

FIELD OF EMBODIMENTS OF THE INVENTION

Some applications of the present invention generally relate to implantedmedical apparatus. Specifically, some applications of the presentinvention relate to self-suturing anchors.

BACKGROUND

The mitral valve is located at the junction between the left atrium andthe left ventricle of the heart. During diastole, the valve opens, inorder to allow the flow of blood from the left atrium to the leftventricle. During systole, when the left ventricle pumps blood into thebody via the aorta, the valve closes to prevent the backflow of bloodinto the left atrium. The mitral valve is composed of two leaflets (theposterior leaflet and the anterior leaflet), which are located at themitral annulus, the annulus being a ring that forms the junction betweenthe left atrium and the left ventricle. The mitral valve leaflets aretethered to papillary muscles of the left ventricle via chordaetendineae. The chordae tendineae prevent the mitral valve leaflets fromeverting into the left atrium during systole.

Mitral valve regurgitation is a condition in which the mitral valve doesnot close completely, resulting in the backflow of blood from the leftventricle to the left atrium. In some cases, regurgitation is caused bydilation of the mitral annulus, and, in particular, by an increase inthe anteroposterior diameter of the mitral annulus. Alternatively oradditionally, mitral regurgitation is causes by dilation of the leftventricle that, for example, may result from an infarction. The dilationof the left ventricle results in the papillary muscles consistentlytethering the mitral valve leaflets into an open configuration, via thechordae tendineae.

SUMMARY OF EMBODIMENTS

For some applications of the present invention, the mitral annulus andthe left ventricle of a subject are reshaped in order to treat mitralregurgitation. Typically, a P1-anchor, a P2-anchor, and a P3-anchor, areanchored to tissue in the vicinity of, respectively, P1, P2 and P3segments of the posterior leaflet of the mitral valve. A tether thatpasses through the anchors is pulled and anchored to an anchoringlocation that is at a cardiac site that is anterior and inferior to theposterior leaflet, e.g., in the vicinity of the apex of the heart.Typically, the pulling of the tether decreases the circumference of themitral annulus. The anchoring of the tether to the cardiac site causesthe anteroposterior diameter of the mitral annulus to decrease, andreshapes the left ventricle such that tethering of the mitral leafletsby the chordae tendineae is reduced.

Typically, a healthy mitral annulus has a saddle shape. The saddle shapeof a healthy mitral annulus further reduces the circumference of theannulus (due to folding of the mitral leaflets), and reduces leafletstress, relative to a flattened annulus. In some diseased mitral valves,the annulus dilates such that the saddle shape of the annulus isflattened. For some applications of the present invention, the tetherthat passes through the P1, P2, and P3 anchors is fixedly coupled to theP2 anchor, and is slidably coupled to the P1 and P3 anchors. For someapplications, fixedly coupling the tether to the P2 anchor, and slidablycoupling the anchor to the P1 and P3 anchors results in inferior motionof the P1 and P3 anchors relative to the P2 anchor, when the tether ispulled and anchored to the anchoring location, as described hereinabove.In turn, this results in the restoration of a saddle-shape to theannulus.

For some applications, a ring is implanted in the vicinity of (e.g., onor posterior to) the mitral annulus. Typically, the ring is implanted onthe posterior mitral annulus, in order to reduce the circumference ofthe mitral annulus. A plurality (e.g., three) self-suturing anchors aredisposed inside the ring. The anchors are shaped to define openingstherethrough, and a mandrel is reversibly disposed through the openings.In response to the removal of the mandrel from the openings, the anchorsautomatically become coupled to a leaflet of the mitral valve.Typically, re-inserting the mandrel through the openings, results ineach of the anchors exiting the tissue via an exit route that is thereverse of the entry route of the anchor.

There is therefore provided, in accordance with some applications of thepresent invention, apparatus for use with a mitral valve of a heart of asubject, the apparatus including:

a P1-anchor, a P2-anchor, and a P3-anchor, configured to become anchoredto tissue in a vicinity of, respectively, P1, P2 and P3 segments of aposterior leaflet of the mitral valve, a tether being fixedly coupled tothe P2-anchor, and slidably coupled to the P1 and P3 anchors; and

a cardiac-site anchor configured to anchor the tether to an anchoringlocation that is at a cardiac site that is anterior and inferior to theposterior leaflet.

For some applications, the cardiac-site anchor includes a clip.

For some applications, the P1-anchor, the P2-anchor, and the P3-anchorinclude clips.

For some applications, the clips are shaped to define openingstherethrough, the apparatus further includes a mandrel configured to bereversibly disposed through the openings, and, in response to removingthe mandrel from the openings, the clips are configured to automaticallybecome anchored to the tissue.

For some applications, the apparatus further includes a mitral ringconfigured to become coupled to the tissue by the anchors.

For some applications, the mitral ring includes compressible portionthereof, the compressible portions being disposed between adjacentanchors of the anchors.

There is further provided, in accordance with some applications of thepresent invention, a method of treating a mitral valve of a heart of asubject, the method comprising:

reducing a circumference of a mitral annulus and restoring asaddle-shape of the mitral annulus, by:

-   -   anchoring a P1-anchor, a P2-anchor, and a P3 -anchorto tissue in        a vicinity of, respectively, P1, P2 and P3 segments of a        posterior leaflet of the mitral valve, a tether being fixedly        coupled to the P2-anchor, and slidably coupled to the P1 and P3        anchors;    -   subsequently, pulling the tether; and    -   anchoring the tether to an anchoring location that is at a        cardiac site that is anterior and inferior to the posterior        leaflet.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an inner surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an outer surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the P1-anchor, the P2 -anchor,and theP3-anchor includes inserting the anchors transmyocardially into a leftatrium of the subject, and anchoring the anchors to a left atrial sideof the posterior leaflet of the mitral valve.

For some applications, the P1-anchor, the P2-anchor, and the P3-anchorinclude a P1-clip, a P2-clip, and a P3 -clip,and anchoring theP1-anchor, the P2-anchor, and the P3-anchor includes inserting the clipsinto a left ventricle of the subject and clipping the clips to a leftventricular side of the posterior leaflet of the mitral valve, such thatthe clips penetrate tissue of the posterior leaflet.

For some applications, anchoring the tether to the anchoring locationincludes decreasing a ratio of an anteroposterior diameter of the mitralannulus to a lateral diameter of the mitral annulus.

For some applications, anchoring the tether to the anchoring locationincludes reshaping a left ventricle of the subject.

For some applications, the anchors are shaped to define openingstherethrough, and anchoring the anchors includes causing the anchors tobecome anchored automatically, by removing a mandrel from inside theopenings defined by the anchors.

For some applications, the anchors are coupled to a ring, and anchoringthe anchors to the tissue includes coupling the ring to the tissue.

There is additionally provided, in accordance with some applications ofthe present invention, a method of treating a mitral valve of a heart ofa subject, the method comprising:

reducing a circumference of a mitral annulus and reshaping a leftventricle, by:

-   -   anchoring a P1-anchor, a P2-anchor, and a P3 -anchorto tissue in        a vicinity of, respectively, P1, P2 and P3 segments of a        posterior leaflet of the mitral valve;    -   subsequently, pulling a tether that passes through the anchors;        and    -   anchoring the tether to an anchoring location that is at a        cardiac site that is anterior and inferior to the posterior        leaflet.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an inner surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an outer surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the P1-anchor, the P2 -anchor,and theP3-anchor includes inserting the anchors transmyocardially into a leftatrium of the subject, and anchoring the anchors to a left atrial sideof the posterior leaflet of the mitral valve.

For some applications, the P1-anchor, the P2-anchor, and the P3-anchorinclude a P1-clip, a P2-clip, and a P3 -clip,and anchoring theP1-anchor, the P2-anchor, and the P3-anchor includes inserting the clipsinto a left ventricle of the subject and clipping the clips to a leftventricular side of the posterior leaflet of the mitral valve, such thatthe clips penetrate tissue of the posterior leaflet.

For some applications, anchoring the tether to the anchoring locationincludes decreasing a ratio of an anteroposterior diameter of the mitralannulus to a lateral diameter of the mitral annulus.

For some applications, anchoring the tether to the anchoring locationincludes restoring a saddle-shape of the mitral annulus.

For some applications, anchoring the P1-anchor, the P2 -anchor, and theP3-anchor includes anchoring the anchors to the tissue, the tether beingfixedly coupled to the P2 -anchor, and slidably coupled to the P1 and P3anchors.

For some applications, the anchors are shaped to define openingstherethrough, and anchoring the anchors includes causing the anchors tobecome anchored automatically, by removing a mandrel from inside theopenings defined by the anchors.

For some applications, the anchors are coupled to a ring, and anchoringthe anchors to the tissue includes coupling the ring to the tissue.

There is further provided, in accordance with some applications of thepresent invention, a method of treating a mitral valve of a heart of asubject, the method comprising:

reducing a circumference of a mitral annulus and decreasing a ratio ofan anteroposterior diameter of the mitral annulus to a lateral diameterof the mitral annulus, by:

-   -   anchoring a P1-anchor, a P2-anchor, and a P3 -anchorto tissue in        a vicinity of, respectively, P1, P2 and P3 segments of a        posterior leaflet of the mitral valve;    -   subsequently, pulling a tether that passes through the anchors;        and    -   anchoring the tether to an anchoring location that is at a        cardiac site that is anterior and inferior to the posterior        leaflet.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an inner surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an outer surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the P1-anchor, the P2 -anchor, and theP3-anchor includes inserting the anchors transmyocardially into a leftatrium of the subject, and anchoring the anchors to a left atrial sideof the posterior leaflet of the mitral valve.

For some applications, the P1-anchor, the P2-anchor, and the P3-anchorinclude a P1-clip, a P2-clip, and a P3 -clip, and anchoring theP1-anchor, the P2-anchor, and the P3-anchor includes inserting the clipsinto a left ventricle of the subject and clipping the clips to a leftventricular side of the posterior leaflet of the mitral valve, such thatthe clips penetrate tissue of the posterior leaflet.

For some applications, anchoring the tether to the anchoring locationincludes reshaping a left ventricle of the subject.

For some applications, anchoring the tether to the anchoring locationincludes restoring a saddle-shape of the mitral annulus.

For some applications, anchoring the P1-anchor, the P2 -anchor, and theP3-anchor includes anchoring the anchors to the tissue, the tether beingfixedly coupled to the P2 -anchor, and slidably coupled to the P1 and P3anchors.

For some applications, the anchors are shaped to define openingstherethrough, and anchoring the anchors includes causing the anchors tobecome anchored automatically, by removing a mandrel from inside theopenings defined by the anchors.

For some applications, the anchors are coupled to a ring, and anchoringthe anchors to the tissue includes coupling the ring to the tissue.

There is further provided, in accordance with some applications of thepresent invention, apparatus, including:

a plurality of anchoring elements, each of the anchoring elements beingan elongate element that is curved to define an opening;

a housing configured to hold each of the anchoring elements; and

a mandrel that is reversibly disposable through the openings defined bythe anchoring elements.

the anchoring elements being configured such that, in response toremoval of the mandrel from the openings, ends of the anchoring elementsautomatically move outwardly, and diameters of the openings decrease,due to elastic loading of the anchoring elements.

For some applications, ends of the anchoring elements are sharp.

For some applications, each of the anchoring elements is configured toautomatically become anchored to tissue of a subject, by entering thetissue via an entry route, in response to removal of the mandrel fromthe opening defined by the anchoring element.

For some applications, each of the anchoring elements is configured toautomatically exit the tissue via an exit route that is a reverse of theentry route, in response to reinsertion of the mandrel through theopening.

For some applications, the anchoring elements are configured to couplethe housing to the tissue by becoming anchored to the tissue.

For some applications, the housing includes flexible portions thereof,the flexible portions being disposed between adjacent anchoring elementsof the anchoring elements.

For some applications, the anchoring elements include a P1-anchor, aP2-anchor, and a P3-anchor configured to become coupled to tissue in avicinity of, respectively, P1, P2 and P3 segments of a posterior leafletof the mitral valve.

For some applications, the apparatus further includes a tetherconfigured to pass through the anchors.

For some applications, the tether is fixedly coupled to the P2-anchorand is slidably coupled to the P1-anchor and the P3-anchor.

For some applications, the apparatus further includes a cardiac-siteanchor configured to anchor ends of the tether to a cardiac site of aheart of a subject.

There is additionally provided, in accordance with some applications ofthe present invention, apparatus, including:

a plurality of anchoring elements;

a mandrel that is reversibly disposable through the anchoring elements,

each of the anchoring elements being configured to:

-   -   automatically become anchored to tissue of a subject, by        entering the tissue via an entry route, in response to removal        of the mandrel from the anchoring element; and    -   subsequently, automatically exit the tissue via an exit route        that is a reverse of the entry route, in response to reinsertion        of the mandrel through the anchoring element.

For some applications, ends of the anchoring elements are sharp.

For some applications, each of the anchoring elements includes anelongate element that is curved to define an opening, the mandrel isreversibly disposable through the openings, and ends of respectiveanchoring elements are configured to automatically become anchored tothe respective locations of the tissue by moving outwardly, in responseto removal of the mandrel from the openings.

For some applications, the anchoring elements are configured such that,in response to removal of the mandrel from the openings, ends of theanchoring elements automatically move outwardly, and diameters of theopenings decrease, due to elastic loading of the anchoring elements.

For some applications, the anchoring elements are disposed in a housing,and the anchoring elements are configured to couple the housing to thetissue by becoming anchored to the tissue.

For some applications, the housing includes flexible portions thereof,the flexible portions being disposed between adjacent anchoring elementsof the anchoring elements.

For some applications, the anchoring elements include a P1-anchor, aP2-anchor, and a P3-anchor configured to become coupled to tissue in avicinity of, respectively, P1, P2 and P3 segments of a posterior leafletof the mitral valve.

For some applications, the apparatus further includes a tetherconfigured to pass through the anchors.

For some applications, the tether is fixedly coupled to the P2-anchorand is slidably coupled to the P1-anchor and the P3-anchor.

For some applications, the apparatus further includes a cardiac-siteanchor configured to anchor ends of the tether to a cardiac site of aheart of a subject.

There is further provided, in accordance with some applications of thepresent invention, a method, including:

inserting a plurality of anchoring elements into tissue of a subject byremoving a mandrel from the anchoring elements, each of the anchoringelements being configured to enter the tissue via an entry route; and

subsequently, causing each of the anchoring elements to automaticallyexit the tissue via an exit route in response to reinsertion of themandrel through the anchoring elements, the exit route of each anchoringelement being a reverse of the entry route of the anchoring element.

For some applications, the anchoring elements include anchoring elementsthat are elongate elements that are curved to define openings, andinserting the plurality of anchoring elements into the tissue includescausing ends of the anchoring elements to automatically become anchoredto respective locations of the tissue by moving outwardly, by removingthe mandrel from the openings.

For some applications, the tissue includes prosthetic tissue, andinserting the anchors into the tissue includes inserting the anchorsinto the prosthetic tissue.

For some applications, the tissue includes natural tissue, and insertingthe anchors into the tissue includes inserting the anchors into thenatural tissue.

For some applications, the tissue includes tissue at a site selectedfrom the group consisting of a site of gastrointestinal tract of thesubject and a cardiac site of the subject, and inserting the anchorsinto the tissue includes inserting the anchors into the tissue at theselected site.

For some applications, inserting the plurality of anchoring elementsinto the tissue includes anchoring a P1 -anchor, a P2-anchor, and aP3-anchor, to tissue in a vicinity of, respectively, P1, P2 and P3segments of a posterior leaflet of the mitral valve.

For some applications, the method further includes pulling a tether thatpasses through the anchors, and anchoring the tether to an anchoringlocation that is at a cardiac site that is anterior and inferior to theposterior leaflet.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an inner surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an outer surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the P1-anchor, the P2-anchor, and theP3-anchor includes inserting the anchors into a left atrium of thesubject, and anchoring the anchors to a left atrial side of theposterior leaflet of the mitral valve.

For some applications, anchoring the P1-anchor, the P2-anchor, and theP3-anchor includes inserting the anchors into a left ventricle of thesubject and inserting the anchors into a left ventricular side of theposterior leaflet of the mitral valve, such that the anchors penetratetissue of the posterior leaflet.

For some applications, anchoring the tether to the anchoring locationincludes decreasing a ratio of an anteroposterior diameter of a mitralannulus of the subject to a lateral diameter of the mitral annulus.

For some applications, anchoring the tether to the anchoring locationincludes restoring a saddle-shape of a mitral annulus of the subject.

For some applications, anchoring the tether to the anchoring locationincludes decreasing a circumference of a mitral annulus of the subject.

For some applications, anchoring the tether to the anchoring locationincludes reshaping a left ventricle of the subject.

For some applications, anchoring the P1-anchor, the P2-anchor, and theP3-anchor includes anchoring the anchors to the tissue, a tether beingfixedly coupled to the P2 -anchor, and slidably coupled to the P1 and P3anchors.

There is further provided, in accordance with some applications of thepresent invention, apparatus for use with tissue of a subject,including:

a plurality of anchoring elements configured to become anchored torespective locations of the tissue, each of the anchoring elements beingan elongate element that is curved to define an opening;

a housing configured to hold each of the anchoring elements, duringanchoring of the anchoring elements to the tissue; and

a mandrel that is disposed through the openings defined by the anchoringelements,

ends of the anchoring elements being configured to automatically becomeanchored to the respective locations of the tissue by moving outwardly,in response to removal of the mandrel from the openings.

For some applications, ends of the anchoring elements are sharp.

For some applications, the anchoring elements are configured such that,in response to removal of the mandrel from the openings, ends of theanchoring elements automatically move outwardly, and diameters of theopenings decrease, due to elastic loading of the anchoring elements.

For some applications, each of the anchoring elements is configured toautomatically become anchored to tissue of a subject, by entering thetissue via an entry route, in response to removal of the mandrel fromthe opening defined by the anchoring element.

For some applications, each of the anchoring elements is configured toautomatically exit the tissue via an exit route that is a reverse of theentry route, in response to reinsertion of the mandrel through theopening.

For some applications, the anchoring elements are configured to couplethe housing to the tissue by becoming anchored to the tissue.

For some applications, the housing includes flexible portions thereof,the flexible portions being disposed between adjacent anchoring elementsof the anchoring elements.

For some applications, the anchoring elements include a P1-anchor, aP2-anchor, and a P3-anchor configured to become coupled to tissue in avicinity of, respectively, P1, P2 and P3 segments of a posterior leafletof the mitral valve.

For some applications, the apparatus further includes a tetherconfigured to pass through the anchors.

For some applications, the tether is fixedly coupled to the P2-anchorand is slidably coupled to the P1-anchor and the P3-anchor.

For some applications, the apparatus further includes a cardiac-siteanchor configured to anchor ends of the tether to a cardiac site of aheart of a subject.

There is additionally provided, in accordance with some applications ofthe present invention, a method for use with tissue of a subject,including:

providing a plurality of anchoring elements, each of the anchoringelements being an elongate element that is curved to define an opening,and a mandrel that is disposed through the openings defined by theanchoring elements; and

causing ends of the anchoring elements to automatically become anchoredto respective locations of the tissue by moving outwardly, by removingthe mandrel from the openings.

For some applications, causing the ends of the anchoring elements toautomatically become anchored to respective locations of the tissueincludes causing each of the anchoring elements to enter tissue via anentry route, the method further including, subsequently, causing each ofthe anchoring elements to automatically exit the tissue via an exitroute in response to reinsertion of the mandrel through the anchoringelements, the exit route of each anchoring element being a reverse ofthe entry route of the anchoring element.

For some applications, the tissue includes prosthetic tissue, andinserting the anchors into the tissue includes inserting the anchorsinto the prosthetic tissue.

For some applications, the tissue includes natural tissue, and insertingthe anchors into the tissue includes inserting the anchors into thenatural tissue.

For some applications, the tissue includes tissue at a site selectedfrom the group consisting of a site of a gastrointestinal tract of thesubject and a cardiac site of the subject, and inserting the anchorsinto the tissue includes inserting the anchors into the tissue at theselected site.

For some applications, inserting the plurality of anchoring elementsinto the tissue includes anchoring a P1 -anchor, a P2-anchor, and aP3-anchor, to tissue in a vicinity of, respectively, P1, P2 and P3segments of a posterior leaflet of the mitral valve.

For some applications, the method further includes pulling a tether thatpasses through the anchors, and anchoring the tether to an anchoringlocation that is at a cardiac site that is anterior and inferior to theposterior leaflet.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an inner surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the anchor to the anchoring locationincludes anchoring the anchor to an outer surface of the heart at avicinity of an apex of the heart.

For some applications, anchoring the P1-anchor, the P2-anchor, and theP3-anchor includes inserting the anchors into a left atrium of thesubject, and anchoring the anchors to a left atrial side of theposterior leaflet of the mitral valve.

For some applications, anchoring the P1-anchor, the P2-anchor, and theP3-anchor includes inserting the anchors into a left ventricle of thesubject and inserting the anchors into a left ventricular side of theposterior leaflet of the mitral valve, such that the anchors penetratetissue of the posterior leaflet.

For some applications, anchoring the tether to the anchoring locationincludes decreasing a ratio of an anteroposterior diameter of a mitralannulus of the subject to a lateral diameter of the mitral annulus.

For some applications, anchoring the tether to the anchoring locationincludes restoring a saddle-shape of a mitral annulus of the subject.

For some applications, anchoring the tether to the anchoring locationincludes decreasing a circumference of a mitral annulus of the subject.

For some applications, anchoring the tether to the anchoring locationincludes reshaping a left ventricle of the subject.

For some applications, anchoring the P1-anchor, the P2-anchor, and theP3-anchor includes anchoring the anchors to the tissue, a tether beingfixedly coupled to the P2 -anchor, and slidably coupled to the P1 and P3anchors.

The present invention will be more fully understood from the followingdetailed description of embodiments thereof, taken together with thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-E are schematic illustrations of a mitral valve and a leftventricle being reshaped via a transapical approach, in accordance withsome applications of the present invention;

FIGS. 2A-D are schematic illustrations of a mitral valve and a leftventricle being reshaped via a transaortic retrograde approach, inaccordance with some applications of the present invention;

FIGS. 3A-E are schematic illustrations of a mitral valve and a leftventricle being reshaped using clips to anchor a tether to cardiactissue, in accordance with some applications of the present invention;

FIGS. 4A-C are schematic illustrations of anchors being applied to avicinity of the posterior mitral valve leaflet via a transmyocardialapproach, in accordance with some applications of the present invention;

FIGS. 5A-D are schematic illustrations of anchors being applied to avicinity of the posterior mitral valve leaflet via a transmyocardialapproach, in accordance with alternative applications of the presentinvention;

FIGS. 6A-C are schematic illustrations of anchors being applied to avicinity of the posterior mitral valve leaflet via a transmyocardialapproach, in accordance with further alternative applications of thepresent invention;

FIG. 7 is a schematic illustration of anchors being applied to avicinity of the posterior mitral valve leaflet via a transaorticretrograde transmyocardial approach, in accordance with someapplications of the present invention;

FIGS. 8A-H are schematic illustrations of a mitral ring, self-suturinganchors being disposed inside the mitral ring, in accordance with someapplications of the present invention;

FIGS. 9A-I are schematic illustrations of the mitral ring beingimplanted on the atrial side of the posterior mitral valve, inaccordance with some applications of the present invention; and

FIGS. 10A-J are schematic illustrations of the mitral ring beingimplanted on the ventricular side of the posterior mitral valve via atransaortic retrograde approach, in accordance with some applications ofthe present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference is now made to FIGS. 1A-E, which are schematic illustrationsof a mitral valve 20 and a left ventricle 22 being reshaped via atransapical approach, in accordance with some applications of thepresent invention. As shown in FIG. 1A, a P1-anchor P1, a P2-anchor P2,and a P3-anchor P3 are coupled to tissue in the vicinity of,respectively, the P1, P2 and P3 segments of the posterior mitral valveleaflet. For example, the clips may be coupled to tissue on, orposterior to the P1, P2, and P3 segments (e.g., to respective locationsof the mitral annulus)

Anchors P1, P2 and P3 typically include any anchors, clips, and/orpledgets, as are known in the art. For example, the anchors may includeclips that comprise a shape-memory alloy, such as nitinol. For someapplications, anchors as described in U.S. Pat. No. 7,056,325 toMakower, which is incorporated herein by reference, are used. For someapplications, clips (e.g., The U-Clip® manufactured by Medtronic(Minneapolis, Minn.)) are used as anchors, for example, as describedhereinbelow with reference to FIGS. 3A-F. For some applications, amitral ring that includes self-suturing clips, as described hereinbelowwith reference to FIGS. 8-10, is used for anchors P1, P2 and P3.Typically, a tissue penetrating sheath penetrates the cardiac musclebehind the posterior leaflet, so as to place the anchors on the atrialside of the posterior leaflet, as described in further detailhereinbelow, with reference to FIGS. 4-7. The penetrating sheath isinserted via a delivery catheter 24, shown in FIG. 1A, for example.

As shown in FIG. 1B, a tether 30, which passes through anchors P1, P2,and P3 is pulled and anchored to an anchoring location 32 that is at acardiac site that is anterior and inferior to the posterior leaflet,e.g., the outside surface of the heart in the vicinity of the apex ofthe heart, as shown. Typically, the tether is pulled and anchored tolocation 32 such that

-   -   the circumference of the mitral annulus decreases (due to the        P1, P2, and P3 anchors being pulled anteriorly)    -   a ratio of the anteroposterior diameter of the annulus to the        lateral diameter of the annulus decreases (due to the P1, P2,        and P3 anchors being pulled anteriorly)    -   the distance D (shown in FIGS. 1A and 1C) from the papillary        muscles to the posterior leaflet decreases (due to tension in        tether 30 pulling the inferior wall of the left ventricle toward        the posterior leaflet).

Typically, tether 30 is fixedly coupled to anchor P2, e.g., via a knot34, as shown in FIG. 1D. The tether is slidably coupled to the P1 and P3anchors. For some applications, this results in the P1 and P3 anchorsbeing pulled inferiorly with respect to the P2 anchor, when tether 30 ispulled, as shown in FIG. 1E. Typically, this restores a saddle-shape toa mitral annulus 36 that has become misshapen due to dilation of theannulus. As described hereinabove, the saddle-shape of the annulusfurther reduces the circumference of the annulus, and/or reduces tensionin the mitral valve leaflets, relative to a flattened mitral annulus.

For some applications, tether 30 is pulled through the anchors during abeating heart procedure, such that the degree of functional change canbe controlled during the procedure, and observed under functionalimaging (e.g., echocardiography). Typically, the tether is pulled andanchored in response to the real-time functional imaging, for example,such that an optimal hemodynamic response is achieved.

Reference is now made to FIGS. 2A-D, which are schematic illustrationsof mitral valve 20 and left ventricle 22 being reshaped via atransaortic retrograde approach, in accordance with some applications ofthe present invention. As shown in FIG. 2A, for some applications,anchors P1, P2, and P3, and tether 30 are inserted into the subject'sheart via a transaortic retrograde approach. The placement of theanchors is generally similar to that described hereinabove, withreference to FIGS. 1A-E, except that delivery catheter 24 is insertedvia the aorta, rather than via the apex of the heart. Subsequent to theplacement of the anchors, tether is pulled, and is anchored to anchoringlocation 32, which may be on the inner surface of the myocardium, forexample, in the vicinity of the apex of the heart, as shown in FIGS.2B-D.

Reference is now made to FIGS. 3A-F, which are schematic illustrationsof mitral valve 20 and left ventricle 22 being reshaped, using clips asthe P1, P2, and P3 anchors, in accordance with some applications of thepresent invention. FIG. 3A-F shows the clips being used in a transaorticretrograde technique, although the clips can also be used in combinationwith the other techniques described herein, mutatis mutandis. Typically,delivery catheter 24 inserts the clips into tissue from a ventricularside of the valve. The clips are typically inserted such that the clipspenetrate the tissue and the tips of the clips enter atrium 40. Tether30 passes through the clips, and the ends of the tether are anchored toanchoring location, as described hereinabove, and as shown in FIGS.3B-D.

Typically, anchor P2 is fixedly coupled to tether 30, e.g., via knot 34,as shown in FIG. 3E. Further typically, the tether is slidably coupledto the P1 and P3 anchors, as indicated by arrow 42 in FIG. 3E. Thus,when the tether is pulled toward anchoring site 32, which is anteriorand inferior to the posterior leaflet, anchors P1 and P3 slide towardanchor P2, and are pulled inferiorly with respect to anchor P2.

As described hereinabove, with reference to FIGS. 3A-E, for someapplications, clips are inserted from the ventricle into the posteriormitral valve leaflet, such that the clips penetrate the leaflet.Alternatively, anchors are placed on the atrial side of the posteriormitral valve leaflet. For some applications, the anchors are placed onthe atrial side of the posterior valve leaflet via a transmyocardialapproach, in accordance with the techniques described with reference toFIGS. 4-7.

Reference is now made to FIGS. 4A-C, which are schematic illustrationsof anchors P1, P2, and P3 being applied to tissue in the vicinity of theposterior mitral valve leaflet via a transmyocardial approach, inaccordance with some applications of the present invention. Apenetrating sheath 50 is inserted into the left ventricle, via deliverycatheter 24. The penetrating sheath is advanced such that the sheathpenetrates the myocardium, and the distal tip of the sheath is disposedin atrium 40, as shown in FIG. 4A. Subsequently, an anchor-deliverysheath 52 is advanced out of the distal end of penetrating sheath 50.The P1, P2 and P3 anchors are delivered and anchored to atrial tissuethat is in the vicinity of (e.g., on or posterior to) the posteriorleaflet of the mitral valve, via the anchor-delivery sheath. FIG. 4Cillustrates the delivery and placement of the P1 anchor viaanchor-delivery sheath 52.

Reference is now made to FIGS. 5A-D, which are schematic illustrationsof anchors P1, P2, and P3 being applied to tissue in the vicinity of theposterior mitral valve leaflet via a transmyocardial approach, inaccordance with alternative applications of the present invention. Forsome applications, penetrating sheath 50 is inserted into left ventricle22 via anchor-delivery sheath 52, which, in turn, is inserted viadelivery catheter 24, as shown in FIG. 5A. The penetrating sheath isadvanced such that the sheath penetrates the myocardium, and the distaltip of the sheath is disposed in atrium 40, as shown in FIG. 5B.Subsequently, penetrating sheath is withdrawn from anchor-deliverysheath 52 (shown in FIG. 5C), and the anchors are delivered to the leftatrium via the anchor delivery sheath. FIG. 5D illustrates the deliveryand placement of the P1 anchor via anchor-delivery sheath 52.

Reference is now made to FIGS. 6A-C, which are schematic illustrationsof anchors P1, P2, and P3 being applied to the posterior mitral valveleaflet via a transmyocardial approach, in accordance with furtheralternative applications of the present invention. For someapplications, a single sheath 50 penetrates the myocardium, and deliversthe anchors to the tissue of the left atrium. As shown in FIGS. 6A-C,for some applications, penetrating sheath 50 defines openings 54, 56,and 58, via which, respectively, P1, P2, and P3 anchors are delivered.The distal tip of the penetrating sheath is advanced from the distal endof delivery catheter 24, such that the penetrating sheath penetrates themyocardium, as shown in the transition from FIG. 6A-6B. Subsequently,the penetrating sheath is advanced, such that opening 54 is facingtissue in the vicinity of the P1 segment of the posterior leaflet ofmitral valve 20. Anchor P1 is anchored to the aforementioned tissue, viaopening 54, as shown in FIG. 6C. Subsequently, P2 and P3 anchors areanchored to tissue in the vicinity of, respectively, the P2 and P3segments of the posterior leaflet of mitral valve 20, via openings 56and 58 (not shown).

Reference is now made to FIG. 7, which is a schematic illustration ofanchors P1, P2, and P3 being applied to tissue in the vicinity of theposterior mitral valve leaflet via a transaortic retrogradetransmyocardial approach, in accordance with some applications of thepresent invention. It is noted that in the techniques describedhereinabove, with reference to FIGS. 4-6, penetrating sheath is insertedinto the atrium via a penetration site that is in the vicinity of theanterior commissure of the mitral valve. Anchor-delivery sheath 52 orpenetrating sheath 50 is then advanced from the aforementionedpenetration site to the P1, P2 and P3 segments of the posterior mitralvalve. For alternative applications, penetrating sheath 50 penetratesthe myocardium at a penetrating site that is in the vicinity of theposterior commissure of the mitral valve, as shown in FIG. 7. In allother respects delivery of the anchors via the penetrating sheath (and,optionally, via the anchor-delivery sheath) is generally in accordancewith the techniques described with reference to FIGS. 4-6.

Reference is now made to FIGS. 8A-H, which are schematic illustrationsof a mitral ring 60, self-suturing anchors 62 being disposed inside themitral ring, in accordance with some applications of the presentinvention. Mitral ring 60 is typically made of a polymer, a plastic,titanium, stainless steel, and/or other similar materials. Anchors 62are elongate elements that are shaped to define openings 63. A mandrel64 is reversibly disposed through the openings, as shown in FIGS. 8A-B.In response to the mandrel being withdrawn from the openings, ends 66 ofthe anchors automatically move outwardly, via openings 68 in the mitralring (typically, due to the anchors being elastically loaded), as shownin FIG. 8C.

Typically, while mandrel 64 is disposed inside openings 63 defined byanchors 62, the anchors are placed adjacent to tissue that is in thevicinity of the mitral valve (or other tissue as described hereinbelow).In response to the mandrel being withdrawn from the openings, ends 66 ofthe anchors move outwardly, thereby entering the tissue. Ends 66 aretypically sharp, so as to facilitate penetration of the tissue. For someapplications, in response to mandrel being reinserted via the openingsthat are defined by the anchors, the anchors exit the tissue via exitroutes that are the reverse of the entry routes of the anchors. Thus, ifthe anchors have been inaccurately placed, the anchors may be removedfrom the tissue without causing an additional wound to the tissue,during the removal of the anchors. Typically, a guidewire 65 passesthrough openings 63, and the mandrel is advanced and withdrawn over theguidewire. Thus, the guidewire facilitate reinsertion if the mandrel viathe openings, if necessary. Typically, a tether (e.g., tether 30described hereinabove) passes through the anchors, and is used to tetherthe anchors to each other.

It is noted that for some applications, mitral ring 60 includes flexibleregions 70 between adjacent anchors. The function of the flexibleregions is described in further detail hereinbelow.

FIGS. 8D, 8E, and 8F show a single anchor, respectively, configured aswhen the mandrel is inserted through opening 63 (FIG. 8D, mandrel notshown), configured as when the mandrel is removed from opening 63 (FIG.8E), and disposed inside mitral ring 60 (FIG. 8F). It is noted that evenin the configuration shown in FIG. 8E (i.e., as when mandrel 64 has beenwithdrawn), the anchor defines an opening 63, via which the mandrel canbe reinserted.

FIGS. 8G-H are schematic illustrations that demonstrate the principle bywhich self-suturing anchors operate. Each anchor is configured such thatwhen mandrel 64 is inserted via opening 63, the anchor is elasticallyloaded, i.e., it is as if there was a loaded spring 72 (shown in dashedlines in FIGS. 8G-H) disposed above the anchor. The spring is preventedfrom expanding by the mandrel. Upon removal of the mandrel from opening,the spring is released, thereby causing the diameter of opening 63 todecrease, and pushing ends 66 outward.

For some applications, the anchors comprise a shape-memory alloy, suchas nitinol. Each anchor is shaped in the closed configuration of theanchor. The mandrel is inserted through the opening in the anchor, suchthat the shape-memory alloy is biased open. Thus, insertion of themandrel through the opening causes the anchor to become elasticallyloaded. Upon removal of the mandrel from the opening of the anchor, theanchor reverts to the closed shape thereof.

For some applications, the anchors comprise a metal, such as stainlesssteel. Each anchor is shaped into the closed configuration of the anchorand becomes elastically loaded due to the insertion of the mandrelthrough the opening in the anchor, as described hereinabove.

Reference is now made to FIGS. 9A-I, which are schematic illustrationsof mitral ring 60 being implanted on the atrial side of the posteriormitral valve, in accordance with some applications of the presentinvention. For some applications, mitral ring is inserted into leftatrium 40 via delivery catheter 24 (FIG. 9A), via the inter-atrialseptum, as shown. Alternatively, the mitral ring is inserted directlyinto the atrium (e.g., via a minimally invasive surgical approach). Themost distal of self suturing anchors 62 of ring 60 is placed adjacent totissue in the vicinity of (e.g., on or posterior to) the P3 segment ofthe posterior mitral valve leaflet (FIG. 9B), Mandrel 64 is withdrawnfrom opening 63 defined by the distal self-suturing anchor, such thatthe anchor automatically becomes anchored to the tissue, due the ends ofthe anchors penetrating the tissue, as described hereinabove (FIG. 9C).

Subsequently, a second one of self suturing anchors 62 of ring 60 isplaced adjacent to tissue in the vicinity of (e.g., on or posterior to)the P2 segment of the posterior mitral valve leaflet (FIG. 9D). Mandrel64 is withdrawn from opening 63 defined by the self-suturing anchor,such that the anchor automatically becomes anchored to the tissue, duethe ends of the anchors penetrating the tissue, as described hereinabove(FIG. 9E).

Further subsequently, a third one of self suturing anchors 62 of ring 60is placed adjacent to tissue in the vicinity of (e.g., on or posteriorto) the P1 segment of the posterior mitral valve leaflet (FIG. 9F).Mandrel 64 is withdrawn from opening 63 defined by the self-suturinganchor, such that the anchor automatically becomes anchored to thetissue, due the ends of the anchors penetrating the tissue, as describedhereinabove (FIG. 9G).

A tether 80 passes through the anchors, and is tied to mitral ring 60 ina vicinity of a first end 82 of the ring that is closest to theposterior commissure. The tether is tightened, so as to pull the anchorstoward each other (FIG. 9H). The tether is then anchored in itstightened configuration, for example, by tying the tether to a secondend 84 of the mitral ring that is closest to the anterior commissure(FIG. 9I). Flexible regions 70 of the mitral ring facilitate themovement of the anchors toward each other, in response to the tighteningof tether 80, by flexing, and/or by becoming compressed. The tighteningof the tether causes a decrease in the circumference of the mitralannulus.

It is noted that, although not shown, for some applications, mitral ring60 is placed on the atrial aspect of the posterior mitral valve, asdescribed with reference to FIGS. 9A-I, and is combined with thetechniques described hereinabove, with reference to FIGS. 1-7, fortethering the posterior leaflet to anchoring location 32, which is at acardiac site that is anterior and inferior to the posterior leaflet.

Reference is now made to FIGS. 10A-J, which are schematic illustrationsof mitral ring 60 being implanted on the ventricular side of theposterior mitral valve via a transaortic retrograde approach, inaccordance with some applications of the present invention. It is notedthat although the mitral ring is shown as being delivered via atransaortic retrograde approach (via delivery catheter 24), for someapplications, the mitral ring is delivered to the ventricular side ofthe posterior mitral valve via a transapical approach.

The mitral ring is passed along the groove between the posterior mitralvalve leaflet and the left ventricular wall, such that first end 82 ofthe mitral ring is in the vicinity of the posterior commissure of themitral valve, as shown in FIG. 10A-C. It is noted, for someapplications, as shown, a first end of tether 30 passes out of the firstend of the mitral ring. Typically, the mitral ring is placed such thatfirst, second, and third self-suturing anchors 62 are adjacent to tissuein the vicinity of (e.g., on or posterior to) the P3, P2, and P1segments of the posterior mitral valve leaflet. Mandrel 64 is withdrawnfrom the openings defined by self-suturing anchors, such that theanchors become anchored to the tissue and act as P1, P2, and P3 anchors,in accordance with the techniques described hereinabove, and as shown inFIGS. 10D-F.

Subsequently, the distal tip of delivery catheter is moved towardanchoring location 32 (FIG. 10G), which, as described hereinabove, is ata cardiac site that is anterior and inferior to the posterior mitralvalve leaflet. Tether 30 is tightened and anchored to anchoring location32, in accordance with the techniques described hereinabove, as shown inFIGS. 10H-J. As shown in FIG. 10J, flexible regions 70 of the mitralring facilitate flexing and compression of the mitral ring, such thatthe anchors are able to move toward each other, and such that the P1 andP3 anchors are able to move inferiorly, relative to the P2 anchor.

It is noted that although self-suturing anchors 62 and ring 60 aredescribed hereinabove as being anchored to tissue associated with themitral valve, the scope of the present invention includes anchoringself-suturing anchors (and, optionally, a housing) to natural orprosthetic tissue of other portions of a subject's body, mutatismutandis.

For example, the anchors may anchor a ring to tissue of a subject'sgastrointestinal tract. For some applications, the anchors and the ringare anchored to tissue in the vicinity of the sphincter muscles that areat the junction between the esophagus and the stomach and the ring istightened in accordance with the techniques described hereinabove, e.g.,in order to treat gastroesophageal reflux disease (GERD). Alternatively,the anchors anchor a ring to the inside of a subject's stomach, and thering is tightened in accordance with the techniques describedhereinabove, in order to treat obesity. Further alternatively, theanchors may be used to treat an atrial or a ventricular septal defect,to close a patent foramen ovale, and/or to treat an abdominal aorticaneurysm.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather, the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove, as well as variations and modifications thereofthat are not in the prior art, which would occur to persons skilled inthe art upon reading the foregoing description.

1. Apparatus, comprising: a plurality of anchoring elements, each of theanchoring elements being an elongate element that is curved to define anopening; a housing configured to hold each of the anchoring elements;and a mandrel that is reversibly disposable through the openings definedby the anchoring elements, the anchoring elements being configured suchthat, in response to removal of the mandrel from the openings, ends ofthe anchoring elements automatically move outwardly, and diameters ofthe openings decrease, due to elastic loading of the anchoring elements.2. The apparatus according to claim 1, wherein ends of the anchoringelements are sharp.
 3. The apparatus according to claim 1, wherein eachof the anchoring elements is configured to automatically become anchoredto tissue of a subject, by entering the tissue via an entry route, inresponse to removal of the mandrel from the opening defined by theanchoring element.
 4. The apparatus according to claim 3, wherein eachof the anchoring elements is configured to automatically exit the tissuevia an exit route that is a reverse of the entry route, in response toreinsertion of the mandrel through the opening.
 5. The apparatusaccording to claim 1, wherein the anchoring elements are configured tocouple the housing to the tissue by becoming anchored to the tissue. 6.The apparatus according to claim 5, wherein the housing comprisesflexible portions thereof, the flexible portions being disposed betweenadjacent anchoring elements of the anchoring elements.
 7. The apparatusaccording to claim 1, wherein the anchoring elements comprise aP1-anchor, a P2-anchor, and a P3-anchor configured to become coupled totissue in a vicinity of, respectively, P1, P2 and P3 segments of aposterior leaflet of the mitral valve.
 8. The apparatus according toclaim 7, further comprising a tether configured to pass through theanchors.
 9. The apparatus according to claim 8, wherein the tether isfixedly coupled to the P2-anchor and is slidably coupled to theP1-anchor and the P3-anchor.
 10. The apparatus according to claim 8,further comprising a cardiac-site anchor configured to anchor ends ofthe tether to a cardiac site of a heart of a subject.
 11. Apparatus,comprising: a plurality of anchoring elements; a mandrel that isreversibly disposable through the anchoring elements, each of theanchoring elements being configured to: automatically become anchored totissue of a subject, by entering the tissue via an entry route, inresponse to removal of the mandrel from the anchoring element; andsubsequently, automatically exit the tissue via an exit route that is areverse of the entry route, in response to reinsertion of the mandrelthrough the anchoring element.
 12. The apparatus according to claim 11,wherein ends of the anchoring elements are sharp.
 13. The apparatusaccording to claim 11, wherein each of the anchoring elements comprisesan elongate element that is curved to define an opening, wherein themandrel is reversibly disposable through the openings, and wherein endsof respective anchoring elements are configured to automatically becomeanchored to the respective locations of the tissue by moving outwardly,in response to removal of the mandrel from the openings.
 14. Theapparatus according to claim 13, wherein the anchoring elements areconfigured such that, in response to removal of the mandrel from theopenings, ends of the anchoring elements automatically move outwardly,and diameters of the openings decrease, due to elastic loading of theanchoring elements.
 15. The apparatus according to claim 11, wherein theanchoring elements are disposed in a housing, and wherein the anchoringelements are configured to couple the housing to the tissue by becominganchored to the tissue.
 16. The apparatus according to claim 15, whereinthe housing comprises flexible portions thereof, the flexible portionsbeing disposed between adjacent anchoring elements of the anchoringelements.
 17. The apparatus according to claim 11, wherein the anchoringelements comprise a P1-anchor, a P2-anchor, and a P3-anchor configuredto become coupled to tissue in a vicinity of, respectively, P1, P2 andP3 segments of a posterior leaflet of the mitral valve.
 18. Theapparatus according to claim 17, further comprising a tether configuredto pass through the anchors.
 19. The apparatus according to claim 18,wherein the tether is fixedly coupled to the P2-anchor and is slidablycoupled to the P1-anchor and the P3-anchor.
 20. The apparatus accordingto claim 18, further comprising a cardiac-site anchor configured toanchor ends of the tether to a cardiac site of a heart of a subject. 21.A method, comprising: inserting a plurality of anchoring elements intotissue of a subject by removing a mandrel from the anchoring elements,each of the anchoring elements being configured to enter the tissue viaan entry route; and subsequently, causing each of the anchoring elementsto automatically exit the tissue via an exit route in response toreinsertion of the mandrel through the anchoring elements, the exitroute of each anchoring element being a reverse of the entry route ofthe anchoring element.
 22. The method according to claim 21, wherein theanchoring elements include anchoring elements that are elongate elementsthat are curved to define openings, and wherein inserting the pluralityof anchoring elements into the tissue comprises causing ends of theanchoring elements to automatically become anchored to respectivelocations of the tissue by moving outwardly, by removing the mandrelfrom the openings.
 23. The method according to claim 21, wherein thetissue includes prosthetic tissue, and wherein inserting the anchorsinto the tissue comprises inserting the anchors into the prosthetictissue.
 24. The method according to claim 21, wherein the tissueincludes natural tissue, and wherein inserting the anchors into thetissue comprises inserting the anchors into the natural tissue.
 25. Themethod according to claim 24, wherein the tissue includes tissue at asite selected from the group consisting of a site of a gastrointestinaltract of the subject and a cardiac site of the subject, and whereininserting the anchors into the tissue comprises inserting the anchorsinto the tissue at the selected site.
 26. The method according to claim21, wherein inserting the plurality of anchoring elements into thetissue comprises anchoring a P1-anchor, a P2-anchor, and a P3-anchor, totissue in a vicinity of, respectively, P1, P2 and P3 segments of aposterior leaflet of the mitral valve.
 27. The method according to claim26, further comprising pulling a tether that passes through the anchors,and anchoring the tether to an anchoring location that is at a cardiacsite that is anterior and inferior to the posterior leaflet.
 28. Themethod according to claim 27, wherein anchoring the anchor to theanchoring location comprises anchoring the anchor to an inner surface ofthe heart at a vicinity of an apex of the heart.
 29. The methodaccording to claim 27, wherein anchoring the anchor to the anchoringlocation comprises anchoring the anchor to an outer surface of the heartat a vicinity of an apex of the heart.
 30. The method according to claim27, wherein anchoring the P1-anchor, the P2-anchor, and the P3-anchorcomprises inserting the anchors into a left atrium of the subject, andanchoring the anchors to a left atrial side of the posterior leaflet ofthe mitral valve.
 31. The method according to claim 27, whereinanchoring the P1-anchor, the P2-anchor, and the P3-anchor comprisesinserting the anchors into a left ventricle of the subject and insertingthe anchors into a left ventricular side of the posterior leaflet of themitral valve, such that the anchors penetrate tissue of the posteriorleaflet.
 32. The method according to claim 27, wherein anchoring thetether to the anchoring location comprises decreasing a ratio of ananteroposterior diameter of a mitral annulus of the subject to a lateraldiameter of the mitral annulus.
 33. The method according to claim 27,wherein anchoring the tether to the anchoring location comprisesrestoring a saddle-shape of a mitral annulus of the subject.
 34. Themethod according to claim 27, wherein anchoring the tether to theanchoring location comprises decreasing a circumference of a mitralannulus of the subject.
 35. The method according to claim 27, whereinanchoring the tether to the anchoring location comprises reshaping aleft ventricle of the subject.
 36. The method according to claim 27,wherein anchoring the P1-anchor, the P2-anchor, and the P3-anchorcomprises anchoring the anchors to the tissue, a tether being fixedlycoupled to the P2-anchor, and slidably coupled to the P1 and P3 anchors.37. Apparatus for use with tissue of a subject, comprising: a pluralityof anchoring elements configured to become anchored to respectivelocations of the tissue, each of the anchoring elements being anelongate element that is curved to define an opening; a housingconfigured to hold each of the anchoring elements, during anchoring ofthe anchoring elements to the tissue; and a mandrel that is disposedthrough the openings defined by the anchoring elements, ends of theanchoring elements being configured to automatically become anchored tothe respective locations of the tissue by moving outwardly, in responseto removal of the mandrel from the openings.
 38. The apparatus accordingto claim 37, wherein ends of the anchoring elements are sharp.
 39. Theapparatus according to claim 37, wherein the anchoring elements areconfigured such that, in response to removal of the mandrel from theopenings, ends of the anchoring elements automatically move outwardly,and diameters of the openings decrease, due to elastic loading of theanchoring elements.
 40. The apparatus according to claim 37, whereineach of the anchoring elements is configured to automatically becomeanchored to tissue of a subject, by entering the tissue via an entryroute, in response to removal of the mandrel from the opening defined bythe anchoring element.
 41. The apparatus according to claim 40, whereineach of the anchoring elements is configured to automatically exit thetissue via an exit route that is a reverse of the entry route, inresponse to reinsertion of the mandrel through the opening.
 42. Theapparatus according to claim 37, wherein the anchoring elements areconfigured to couple the housing to the tissue by becoming anchored tothe tissue.
 43. The apparatus according to claim 42, wherein the housingcomprises flexible portions thereof, the flexible portions beingdisposed between adjacent anchoring elements of the anchoring elements.44. The apparatus according to claim 37, wherein the anchoring elementscomprise a P1-anchor, a P2-anchor, and a P3-anchor configured to becomecoupled to tissue in a vicinity of, respectively, P1, P2 and P3 segmentsof a posterior leaflet of the mitral valve.
 45. The apparatus accordingto claim 44, further comprising a tether configured to pass through theanchors.
 46. The apparatus according to claim 45, wherein the tether isfixedly coupled to the P2-anchor and is slidably coupled to theP1-anchor and the P3-anchor.
 47. The apparatus according to claim 45,further comprising a cardiac-site anchor configured to anchor ends ofthe tether to a cardiac site of a heart of a subject.
 48. A method foruse with tissue of a subject, comprising: providing a plurality ofanchoring elements, each of the anchoring elements being an elongateelement that is curved to define an opening, and a mandrel that isdisposed through the openings defined by the anchoring elements; andcausing ends of the anchoring elements to automatically become anchoredto respective locations of the tissue by moving outwardly, by removingthe mandrel from the openings.
 49. The method according to claim 48,wherein causing the ends of the anchoring elements to automaticallybecome anchored to respective locations of the tissue comprises causingeach of the anchoring elements to enter tissue via an entry route, themethod further comprising, subsequently, causing each of the anchoringelements to automatically exit the tissue via an exit route in responseto reinsertion of the mandrel through the anchoring elements, the exitroute of each anchoring element being a reverse of the entry route ofthe anchoring element.
 50. The method according to claim 48, wherein thetissue includes prosthetic tissue, and wherein inserting the anchorsinto the tissue comprises inserting the anchors into the prosthetictissue.
 51. The method according to claim 48, wherein the tissueincludes natural tissue, and wherein inserting the anchors into thetissue comprises inserting the anchors into the natural tissue.
 52. Themethod according to claim 51, wherein the tissue includes tissue at asite selected from the group consisting of a site of a gastrointestinaltract of the subject and a cardiac site of the subject, and whereininserting the anchors into the tissue comprises inserting the anchorsinto the tissue at the selected site.
 53. The method according to claim48, wherein inserting the plurality of anchoring elements into thetissue comprises anchoring a P1-anchor, a P2-anchor, and a P3-anchor, totissue in a vicinity of, respectively, P1, P2 and P3 segments of aposterior leaflet of the mitral valve.
 54. The method according to claim53, further comprising pulling a tether that passes through the anchors,and anchoring the tether to an anchoring location that is at a cardiacsite that is anterior and inferior to the posterior leaflet.
 55. Themethod according to claim 54, wherein anchoring the anchor to theanchoring location comprises anchoring the anchor to an inner surface ofthe heart at a vicinity of an apex of the heart.
 56. The methodaccording to claim 54, wherein anchoring the anchor to the anchoringlocation comprises anchoring the anchor to an outer surface of the heartat a vicinity of an apex of the heart.
 57. The method according to claim54, wherein anchoring the P1-anchor, the P2-anchor, and the P3-anchorcomprises inserting the anchors into a left atrium of the subject, andanchoring the anchors to a left atrial side of the posterior leaflet ofthe mitral valve.
 58. The method according to claim 54, whereinanchoring the P1-anchor, the P2-anchor, and the P3-anchor comprisesinserting the anchors into a left ventricle of the subject and insertingthe anchors into a left ventricular side of the posterior leaflet of themitral valve, such that the anchors penetrate tissue of the posteriorleaflet.
 59. The method according to claim 54, wherein anchoring thetether to the anchoring location comprises decreasing a ratio of ananteroposterior diameter of a mitral annulus of the subject to a lateraldiameter of the mitral annulus.
 60. The method according to claim 54,wherein anchoring the tether to the anchoring location comprisesrestoring a saddle-shape of a mitral annulus of the subject.
 61. Themethod according to claim 54, wherein anchoring the tether to theanchoring location comprises decreasing a circumference of a mitralannulus of the subject.
 62. The method according to claim 54, whereinanchoring the tether to the anchoring location comprises reshaping aleft ventricle of the subject.
 63. The method according to claim 54,wherein anchoring the P1-anchor, the P2-anchor, and the P3-anchorcomprises anchoring the anchors to the tissue, a tether being fixedlycoupled to the P2-anchor, and slidably coupled to the P1 and P3 anchors.